The Wild Hunt has reported on this issue, confirming that Newgrange will indeed be closed this year, see https://wildhunt.org/2020/12/pagan-community-notes-buckland-museum-newgrange-and-stonehenge-to-livestream-solstice-sunrise-more-monoliths-and-other-news.html
“NEWGRANGE, County Meath, Ireland – In a statement released to the media last week, the Office of Public Works in Ireland confirmed the restrictions at the site for Solstice:
“The Office of Public Works’ annual Winter Solstice gathering at the Neolithic Passage Tomb of Newgrange on 21 December has been cancelled this year, due to ongoing COVID-19 restrictions.
“The hugely significant Solstice Sunrise event is to be live-streamed from within the Chamber.”
Each year the rising of the sun on Winter Solstice draws hundreds of people to the site, though only a few who are selected by lottery, are allowed inside the chamber to witness it being illuminated with sunlight. This will be the first year in some time that chamber has been closed for viewing on the Winter Solstice.
Details on where to watch the live stream have not yet been released.
The visitor center for Brú na Bóinne which serves both Newgrange and Knowth re-opened last week after being closed to comply with restrictions due to the pandemic. The outside of Newgrange will remain open for visitors, but the chamber within will continue to be closed to the public.
According to reporting by the Irish Times, those who were entered in the lottery to be present in the chamber for 2020 will be added to the drawing for 2021 since a lottery drawing was not done.
Another UNESCO World heritage site to live stream the Winter Solstice sunset and sunrise is Stonehenge. Most years Stonehenge attracts a large number of people to watch the sunrise and sunset, but this year officials are urging the public to stay away due to concerns over the spread of COVID-19.
One advantage to the live streaming at both sites is that many people from all over the world, rather than just a few able to attend and fit within the space requirements, will be able to watch the sunrise over these historic sites.”
Pilgrims will be allowed to gather outside our sacred sites on the festival days, with the inside of the Bru Na Boine being restricted, probably because of social distancing issues. Makes perfect sense as that space would be very confined.